Resistance unit.



A. A. ZIEGLER.

RESISTANCE UNIT.

APPLICATION FILED MAR.16,1914.

1, 1 1 5 647, Patefited Nov. 3, 1914.

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ALFRED A. ZIEGLEB, or BOSTON, MAssAcHusnr'rs.

RESISTANCE UNIT.

Specification of Letters Patent.

Patented Nov. 3, 1914.

Application filed March is, 1914. Serial no. 824,923.

To all whom it may concern:

Be it known that .I, ALFRED A. ZIEGLER, a citizen of the United States,residing at Boston, in the county of Suffolk and State of Massachusetts.have invented an. Improvement in Resistance Units, of which thefollowing is a specification.

This invention relates to a resistanice unit, and has for its object theconstruction of a device including a resistance-coil andsupporting-means therefor, to. which said coil is detachably connected.Such a, device is of great value in many forms ofsignaling, particularlyrailway-signaling, where resistances of different predetermined valuesare required, as by providing for the ready removal of the coils fromthe supporting-means resistances of different predetermined values maybe supplied, thereby obviating the necessity of employing variableresistances which, require delicate adjustment, and are liable to getout of order. I

My invention also has for its object the provision of improvedmeansincluding attaching-screws for detachably connecting theresistance-coil with its supportingmeans, which enables electricconnection to be maintained in case the attaching-screw or screws workloose. a

Figure 1 is a plan view of a resistanceunit embodying this invention.Fig. 2 1s a side-elevation of the same. Fig. 3 1s an enlarged verticallongitudinal section of an end-portion of the unit. in plan view, of,one oi. the supportlngplates and an end-portion of the baseblock. Fig.5' is a detail of one of the terminal plates "in connection with anendportion of the resistance-coil. -F1g. 6 is an enlarged longitudinalsection of the means vfor detachably connecting a terminal-plate to thesupporting-plate. Fig. 7 is an end view of the spool on which the wireof the resistance-coil is wound.

10 represents the base of the unit which is composed ofinsulating'material. such as porcelain. This base consists of anelongated block'having holes 12 through it for the screws by which itwill be secured to a wall or other sup ort, and having upwardl extendedprojections 13, at each end, wit holes through them to receive screws14, upon the threaded portions of WhlCh are arranged suitablebinding-nuts 15, 16, and interposed washers 17, said screws 14 and Fig.4 is a detail,

nuts and washers arranged thereon constituting the binding-posts. Theterminals of the electric-wires 18 are arranged between the washers 17,or they may be otherwise connected with the binding-posts.

20, represent flat sheet-metal plates with holes through them for thescrews 14, and sald plates are arranged on said screws, as here shown,between the outer faces oi the pro ecting-portions 13, of thebase-block, and the nuts 15, being held in fixed position by said nuts.Said plates have ears 21 which extend inward toward each other, beyondthe inner sides of the projections 13, and said ears have threaded holesthrough them for screws 22, for the. connection therewith of theterminals of the resistancecoil, and said ears also have recesses ornotches 23 in their outer ends to receive projections on said terminals.

The resistance-coil comprises a spool 25, composed of insulatingmateriahas porcelain, on which one or more layers 26 of fine wire arewound, and said spool has a recess orrsocket 27 at each end, preferablycylindrical in form, which extends inward a short distance, and atopposite sides of said recesses or sockets grooves 28 are formed, whichextend, preferably, the entire length thereof, and the heads or ends ofthe spool are formed each with a radial groove 29, in extensions of oneof the side grooves 28 in the adjacent socket. Terminal-plates areal"-ranged at each end of the spool to which the ends of the coil or coilsof wire are soldered or otherwise secured, which plates, as here shown,consists of flat plates 30 of sheetmetal, the inner end-portions ofwhich are made narrower than the outer end-portions, thereby forming ashoulder 31, at the junction of the two end-portions, and said innerend-portions are made of a width corresponding to the diameter ofthesocket at the grooved portions thereof, so that said inner end-portionmay be thrust into the socket with its edges entering the grooves insaid socket, thus being held against rotation with respect to the spool,and said inner end-portion is thrust inward until the shoulder 31 entersthe radial groove 29 in the end of the spool. When thus thrust into thesockets the outer end-portions project from the ends of the spool. Saidterminalplates are additionally secured in place by screws 33 extendedthrough holes in the sides of the spool and through holes in the innerendportions of the plates, and the heads of said screws 33 may be sunkenin holes in the spool and sealed. The outer end-portions of saidterminal plates have transversely arranged recesses 35 in their sides toadmit of their engagement with the shanks of the screws 22, beneath theheads thereof, which recesses are oppositely arranged with respect toeach other. Notwithstanding the screws 22 pass through threaded holes inthe supporting-plates 20, there is a tendency for said screws to workloose, and to maintain electric connection in such event, saidterminal-plates 30, have projections 36 struck out from them, orotherwise formed on them, which enter the recesses or notches 23 in theouter ends of the ears 21 of the supportingplates 20. These projections36 prevent lateral displacement of the terminal-plates with relation tothe supporting-plates when the attaching screws become loosened and thusprevent their detachment from the supporting-plates in such event. Asthe terminal plates are provided with transverse slots in their outerend-portions for quick conn'ection with the attaching-screws, instead ofholes through them for said screws, the provision of such projections 36is of importance, as it enables the employment of terminal-plates withsuch form of slots, and provides for maintaining electric connection ofthe plates when the attaching-screws work loose.

In case it is desired to remove a resistancecoil for the substitution ofanother or for any other purpose, the attaching screws are loosenedsufliciently to admit of disengage ment of the terminal-plates therefromby a movement in a direction lengthwise the screws until the projections36 have disengaged the supporting-plates and then by a transversemovement, although it will be observed that said movements may be easilyand quickly performed by an unskilled person. This is of advantage inrailway signal work, as in case a coil burns out another may be easilyand quickly substituted for it by an unskilled person. Furthermore,resistancecoils such as herein described of predetermined values haveadvantages over a variable resistance, some of these adavantages beingdue tosthe structure and others to the arrangement of the componentparts, hence my invention is not limited to the precise structure hereshown and described.

I claim 1. In a resistance-unit, a base-block of insulating material, apair of binding-posts arranged thereon, a pair of supporting-platesconnected with the binding-posts and having ears extended toward eachother bearing screws, a spool of insulating material, one or more coilsof wire arranged on said spool of a predetermined resistance,terminalplates secured to the ends of said spool to which the ends ofsaid wire are attached,

said terminal-plates extending over the ears of the supporting-plates,and arranged for detachable connection with the screws on said ears,upon a transverse relative movement, said supporting-plates andterminals plates having cooperating means to hold them against lateraldisplacement in case the screws work loose, substantially as described.

2. In a resistance-unit, a base-block of insulating material, a pair ofbinding-posts arranged thereon, a pair of supportingplates arranged inconnection with said binding-posts having ears extended toward eachother with notches at their extremities, a spool of insulating material,one or more coils of wire arranged on said spool, of a predeterminedresistance, terminal-plates secured to the ends of said spool to whichthe ends of said wire are attached, said terminal-plates extending overthe ears of the supporting-plates, and detachably secured thereto, andsaid terminal-plates having downwardly extended projections arranged toenter the notches in said ears, substantially as described.

3. In a resistance-unit, abase-block, bind ing-posts arranged thereon,and a pair of supporting-plates associated with said bindmg-posts havingears extended toward each other the extremity of each ear having anotch, and a spool composed of insulatingmaterial having one or morecoils of wire wound thereon, of a predetermined resistance, and having asocket in each end, terminal-plates at each end of the spool, the innerend-portions of which enter the sockets of the spool and the outerendeportions of which project therefrom, means to secure the innerend-portions in place, the

outer end-portions extending over the supporting-plates and havingtransverse recesses in their sides and screws arranged in connectionwith the supporting-plates beneath the heads of which saidterminalplates are extended, said terminal-plates also having downwardlyextended projections arranged to enter the notches in thesupporting-plates, substantially as described.

4. In a resistance-unit, a spool composed of insulating-material havingone or more coils of wire wound thereon of a predetermined resistance,and having a socket in each end with one or more grooves in its sidewall, a terminal-plate at each end of the spool, the inner end-portionsof which plates enter the grooves in the sockets in the spool and theouter end-portions of which plates project therefrom, means toadditionally secure said inner end-portions in place, the outerend-portions having transverse recesses in their sides to receive screwsby which said terminal-plates are detachably connected to theirsupporting-means, substantially as described.

' end with one or more grooves in its side inner end-portions of whichplates enter the umen 5. In aresistance-unit, a spool composed ofinsulating-material having one or more coils of Wire Wound thereon of apredetermined resistance, and having a socket in each Wall, and a radialgroove in its end in continuation of one of the side grooves, aterminal-plate at each end of the spool, the

grooves in the sockets in the spool and the outer end-portions of Whichplates enter the radial groove and project from the ends of the spool,means to additionally secure the l inner end-portions of saidterminal-plates in place, the outer end-portions thereof having recessesto receive screws by which said terminal-plates are detachably connectedto their supporting-means, substantially as described.

In testimony whereof, I have signed my name to this specification, inthe presence of two subscribing Witnesses.

ALFRED A.. ZIEGLER. i/Vitnesses:

B. J. Norse, H. B. DAvis.

